Differential Regulation of Small RNAs in Response to Aerobic Exercise: Insights into Pathway Modulation and Health Implications

Our goal was to identify effects of the amount and intensity of exercise on skeletal muscle (SkM) small RNA (smRNA), both microRNA (miRNA) and piwi-interacting RNA (piRNA), and their targeted pathways. We extracted total RNA from skeletal muscle (SkM) collected prior to (PRE) and following (POST) a 6–8-month aerobic exercise intervention (n=120; 63M, 57F); smRNA abundance was quantified via untargeted smRNA sequencing. Differentially expressed (DE) smRNA associated with exercise amount or intensity were identified using post-exercise smRNA as the outcome in linear regression modeling controlling for baseline smRNA expression, age, sex, race, BMI Baseline , and percent change in bodyweight; significance was set at p<0.05 and Q<0.1. Pathway analysis was performed on all miRNA, rank ordered on b-estimate, using miEAA analysis tools with significance set at p<0.05. We identified 124 DE smRNAs (114 miRNA; 10 piRNA) responsive to exercise amount and 15 DE smRNA (12 miRNA; 3 piRNA) responsive to exercise intensity; DE miRNAs were functionally related to metabolism, cell cycle, proteostasis, and inflammatory signaling. DE piRNAs had predicted interactions with genomic repeat elements (LTRs and SINEs). LASSO regression selected 21 smRNA and age which explain ~85% of the variance in change in fasting insulin (R 2 =0.859, p<0.001). This study highlights the impact of aerobic exercise on smRNA expression patterns and associated pathways related to metabolism, cell cycle, and inflammatory signaling while also providing insight into insulin signaling via identification of novel smRNA targets selected through LASSO regression. This study was supported by the National Institutes of Health grants R01AG054840 and R01HL153497. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.